Green infrastructure could give Chicago’s sewer system a break

Sinkholes, geysers spewing out of manholes, impassable highways and city streets; the heavy rains over the past week have taken their toll on Chicago’s infrastructure.

An intricate system of major engineering projects executed by the Metropolitan Water Reclamation District and the Army Corps of Engineers including tunnels, reservoirs, locks and levies keep Chicago dry day-in day-out.

But with major rains such as the region has received over the past week, that traditional infrastructure is not enough.

Experts like Ryan Wilson at the Center for Neighborhood Technology in Wicker Park say green infrastructure can relieve the pressure on the water-management systems. While major rainfall will probably still overtax management systems, “we believe using a mix of solutions is the approach that can solve smaller flooding events.”

Wilson recommends a mix of solutions all aimed at reducing the amount of water going into the sewer system. He explained: Permeable pavement can help maximize the ground area absorbing falling rainwater. Rain gardens and natural landscaping can collect water and facilitate absorption. Systems like rain barrels and cisterns collect falling rainwater and allow residents to put it to use.

The technology center connects property owners with resources for implementing projects like these, or what they call “wetrofit” services.

Hal Sprague is a policy expert working with the center. He said that sometimes property owners don’t like the look of these landscaping techniques. “We all have to change our mindset and culture with what we’re used to and comfortable with.”

Finding solutions is important because flooding is expensive. Sprague said “over a 5 year period, 5 to 600 million dollars was spent on claims for flooding in basements and backyards.” That is money that could be going to infrastructure, he said.

However, David J. Yocca, a principal landscape architect and planner at the Conservation Design Forum said green infrastructure planning on a larger scale is also important. Green infrastructure is “not just something you can do one off and reduce neighborhood flooding,” he said.

Yocca and the team at Conservation Design Form designed Chicago’s City Hall green- roof pilot program. Yocca said projects such as green roofs are a good investment because they extend the life of a roof and conserve energy as well as reduce water run off.

Chicago’s green-building permit system encourages developers to introduce green building projects by reducing permit fees and speeding up the permit process.

Chicago’s green ally program is an example of the Department of Transportation’s using green building techniques. Over 100 alleys have been build using permeable pavement and recycled materials. The Department of Transportation is working on a set of sustainable urban infrastructure policies and guidelines, due to be formalized over the summer, that will lay out methods institute green infrastructure in city street construction.

For now, stories of the flooding are valuable. CNT is asking residents to share the flooding stories on their website. Wilson said, “by better understanding what the problem is and the nuance we’ll be better able to plan for the future. The story is raw data.”